This invention relates generally to pool, spa or other water heaters, and more particularly to the extension of the useful lives of such heaters and controls therefor.
In the past, thermostats enclosed in thin-walled copper sleeves were inserted into such heaters so that the water temperature was sensed, for controlling the heater. Such thin-walled sleeves tend to corrode and/or erode relatively rapidly, so that the water would leak to the outside of the heater vessel. This necessitated heater replacement or repair, which is expensive.